1. Field of the Invention
This invention relates to methods and systems for the treatment of valvular disease of the heart. More particularly, this invention relates to monitoring of percutaneous mitral valvuloplasty procedures.
2. Description of the Related Art
A number of different treatments are known or in development to effect minimally invasive mitral valvuloplasty, in order to treat conditions such as mitral regurgitation. One family of solutions takes advantage of the fact that the coronary sinus partially encircles the mitral valve along the atrioventricular groove, generally in the same plane as the mitral valve annulus. A number of companies have developed implants that may be inserted into the coronary sinus and then actuated, typically by mechanical or thermal means to cinch or otherwise constrict the mitral valve annulus. This tends to reduce the radius of curvature of the annulus, which results in improved coaptation of the valve leaflets.
Representative disclosures that exemplify this approach are U.S. Patent Application Publication No. 2003/0083538 and U.S. Pat. No. 6,676,702. Both describe a resilient annuloplasty device, which is percutaneously introduced into the coronary sinus so as to partially encompass the mitral valve annulus. When actuated, the shape of the member is fixed, and it transmits a generally radially directed deforming force on the mitral valve annulus, urging at least a portion of the annulus inwardly.
The left circumflex coronary artery (LCx) runs along the coronary sinus, and at a crossover point it passes under the coronary sinus. The procedures and devices that are currently being employed in the coronary sinus risk compression of the left circumflex coronary artery, and compromise of its blood flow. For example, the above-noted U.S. Pat. No. 6,676,702 cautions that a device placed in the coronary sinus must not be permitted to extend within the coronary sinus beyond the crossover point of the circumflex artery and the coronary sinus to avoid constriction of the left circumflex coronary artery. Even when this precaution is observed, the possibility of aberrant coronary vascular anatomy still creates a risk for the patient.